1. Field of the Invention
The present invention relates to a film loader, or more particularly, to a film loader for such type of camera that performs photography with Patrone-cased film loaded.
2. Description of the Related Art
In a camera that performs photography using Patrone-cased film, the inner circumferential surface of a Patrone chamber in which a Patrone is loaded has, in general, been shaped like the outer circumferential surface of the Patrone in the past. The Patrone chamber, for example, is formed on the rear lateral side in a camera body, and shielded with a back cover.
FIG. 25 shows an example of the above auto-loading type camera, which is an oblique view looking at the camera from above and behind the camera.
The camera has a lens 304 in substantially the center of the front of a camera body 311. In the camera body 311, an aperture 311c is formed behind the lens 304 along the optical axis thereof. A Patrone chamber 311a that accommodates a Patrone 7 is formed at the right of the aperture 311c, and a spool chamber 311d having a spool 312 for taking up film 8 is formed at the left of the aperture 311c. One end of the camera body 311 on the side of the spool chamber 311d has a hinge (not shown) with which a back cover 314 is hinged to be rotatable. The back cover 314 extends from the spool chamber 311d to the Patrone chamber 311a in order to tightly intercept light.
To load film into the above type of camera, first, an operating member 315 located on the side face of the camera body 311 must be operated to disengage a key 316 on the camera body 311 from a key 314a on the back cover 314. Then, the back cover 314 is opened. Then, the Patrone 7 is loaded into the Patrone chamber 311a in an arrow-C direction in FIG. 25. After the distal end of the film 8 is aligned, the back cover 314 is closed in an arrow-D direction in FIG. 25. Consequently, the film 8 is automatically wound around the spool 312.
In a camera recently proposed in Japanese Utility Model Examined Publication No. 1990-10517, a Patrone chamber is slided substantially vertically with respect to the optical axis of a lens and moved to a Patrone loading position, and then a Patrone is loaded in the axial direction thereof.
In a camera proposed in Japanese Patent Laid-Open No. 1988-281142, the open or close operation of a back cover is motor-driven.
As a technical means for sliding a Patrone chamber substantially vertically with respect to the optical axis of a lens, moving the Patrone chamber to a Patrone loading position, and loading a Patrone in the axial direction thereof, which has been disclosed in Japanese Patent Laid-Open No. 1990-176739, a notch is formed in part of the Patrone chamber to improve film loading efficiency.
In the aforesaid conventional construction, when film is to be loaded, a camera is usually positioned with its lens side facing down and with its back cover open. In this state, the film is usually loaded or unloaded. When a camera is fixed to a tripod, however, loading or unloading film is quite a bother.
In recent years, zoom lenses have taken over normal lenses. More and more cameras are having relatively long lens barrels. Therefore, when a camera is placed with its lens side facing down in order to load film, since the camera is quite unstable, the camera sometimes falls down. Besides, excess force is applied to a lens or a barrel, causing the lens or barrel to break.
For overcoming the foregoing drawbacks, a method such as the one described in Japanese Utility Model Examined Publication No. 1990-10517 is thinkable; that is, a Patrone chamber is slided substantially vertically with respect to the optical axis of a lens and moved to a Patrone loading position, and then the Patrone is loaded in the axial direction thereof.
However, the length of a film leader that has already been pulled out of a Patrone to be loaded varies depending on a film manufacturer. In some types of film, a long portion of film has already been pulled out. According to the method described in the above examined publication, a quantity of sliding a Patrone chamber must be large. This leads to an increase in the size of a guide for assisting the Patrone chamber in sliding. Eventually, a camera becomes large.
In a camera based on a quick-loading system, a Patrone loading chamber is locked in the camera. A display operation member is installed in the upper part of the chamber. An aperture through which a Patrone is loaded is usually formed on the bottom of the camera. When the camera is fixed to a tripod, it becomes impossible to replace film.
Furthermore, in a camera having the foregoing conventional construction, the open or close operation of a back cover is not automated. This sometimes leads to an accident that the back cover is opened with film loaded to destroy the exposed invaluable film. The above Japanese Patent Laid-Open No. 1988-281142 does not comment on this problem and may pose a similar drawback.
On the other hand, in a technical means disclosed in the above Japanese Patent Laid-Open No. 1990-176739, a Patrone chamber is structured to be deep in the axial direction of a Patrone. This makes it difficult to extract film from the Patrone chamber. As a solution of this problem, the technical means has a notch in the Patrone chamber. The notch is formed only on one side of the Patrone chamber, leaving a problem that a Patrone is still hard to extract.